1. Field of Invention
The present application relates to mattresses and is a continuation in part application of applicant's current pending application having Ser. No. 07/561,346, filed Aug. 1, 1990, which upon filing of this application is to be abandoned without dedication. More particularly, it relates to a pre-natal mattress having a depression defined upon the top surface to accommodate the protruding abdomen of a pregnant woman. During pregnancy the resultant protruding abdomen often creates difficulties in obtaining comfortable rest for the expectant mother. Sleeping upon her back or side can create back and leg discomfort from fetal pressure upon the spine and these are therefore unfavorable positions. The remaining face downwardly position which would relieve back and abdomen strain is also impractical as the protruding abdomen would preclude comfortable reclining when positioned against a flat supporting surface and possibly cause injury to the fetus. With these limiting conditions present, a number of inventions have been devised to provide a solution to this dilemma.
2. Description of the Relevant Art
U.S. Pat. No. 4,021,872, issued in 1977 to Powell entitled "Maternity Mattress" teaches a foam rubber mattress having a circular cavity defined upon its top surface; this cavity being adjustable in size by virtue of a plurality of removable disc-like members which are removed or replaced as desired.
U.S. Pat. No. 4,054,960, issued in 1977 to Pettit entitled "Inflatable Body Support Cushion Particularly to Support A Woman During Pregnancy" teaches a multi-chambered inflatable mattress having a central aperture for receiving the abdomen of a pregnant woman and a plug for filling said aperture when a flat mattress surface is desired.
Though the above identified devices are useful, they do not teach a cavity filling means which is integral with the mattress and therefore, they would not present a smooth continuous surface to lie upon when so desired, nor are the width and depth of their abdomen accommodating depressions highly adjustable to accommodate women with abdomens of varying widths and depths of protuberance.